Angela, you might try revesing the order of these moves. The fly is not a great exercise for building strength, and it is recommended that you use it as your secondary exercise (it's a stretching move and doing it with too much weight can cause injury to the connective tissue). Using moves that are compound and mid range (employ many muscles) such as the press are always preferable for the main exercise.

Do you have adjustible weights? I have found that doing the shoulder side raises with just the bar after I've worked to failure (or near failure) does a good job of getting me just a little further. The Upright row is another good move for shoulders that is a little easier to do. You might also try doing the shoulder presses from a standing position - it isolates things less (it's a little easier ).

As Karen's tagline says, progress not perfection. One week at a time and come the Fall you'll be amazed at how strong you'll have become.

Nat